Old 30 horse Johnson Update

[JasonJ]

I have since determined that it is in fact a 1956 Johnson 30 hp, model no. RD-18. I spent the day cleaning it. I have no controls, as it is a tiller motor (although controls can be attached). The tiller has been broken off. I also do not have the Johnyrude tank, but I wanted to get it running. I grabbed a cheapy pesticide hand sprayer, the kind you pump up, and ran a hose from it directly to the carb. I dropped the bowl, and the gaskets looked good, there was no junk or varnish in it. I dinked with the two knobs, but since there is no face plate I had no idea what to set them on. After messing with it, I got it running. It ran really well, but since I was not sure what the mix would be, I ran it at 24:1, although I am betting it can run on 50:1 (please let me know). It was really really smoking from the oil. The water pump pumped very well, I left it at a fast idle, problably about 1500 rpm, and I could lay my hand on any part of the engine and the surface was lukewarm. Considering it hasn't ran in at least 5 years if not more, and it is 36 degrees out, it started and ran pretty good. I'll stick new plugs in it, and I think I'll paint it. The gears are good, the lower unit seals looked good, no moisture in the lower unit oil, so for a freebie it is a decent motor. I don't have a compression reading, but considering I am tired, and reached target heart rate pull starting the thing, the compression sure felt good. I'll paint it up and see what I want to do with it after that.

 

[bubbakat]

Re: Old 30 horse Johnson Update

Jason the book says 24:1 and i bet you did get a high heart rate from pulling on that old iron horse. I'll down load that pic I posted for you and try to enhance it to bring out the numbers on the face plate. <br />Glad you got it started<br />I to am going to attempt to start and old johnson that is a 1950 that one of my co-workers has that his dad bought new and it had been stored upright in the barn for 20 years.<br />To say the least it should be interesting i have already fixed the original flat-bottom it came on. it is a 5 h/p<br />keep us posted on your progress<br />BTW that calls for a plug j6c gap at 30

 

[WillyBWright]

Re: Old 30 horse Johnson Update

If your crankshaft and rod bearings are all needle bearings (I'm pretty sure they are), you can run at 50:1. The older 25s (the biggest up until 1956) didn't have all needle bearings and those have to stay with 24:1. You'll need a pressure fuel tank. Gonna be hard to find. Check around. They're out there. But a regular vented tank will not work. Your motor has no fuel pump. It used a 2-hose fuel line, one to pressurize the tank and the other to pass the fuel.

 

[Chinewalker]

Re: Old 30 horse Johnson Update

Hi Jason,<br /> Do not lean it out to 50:1. Although it has roller and needle bearings, it does not have the internal scavenging to properly route enough oil to upper bearings, etc. Also, those old motors are built really loose and if you lean out the oil too much they don't seal up very well, particularly between upper and lower crankcase chambers. It uses the oil as a sealant, in addition to a lubricant. If you want to lean it out a bit, go to 32:1, but no leaner.<br />- Scott

 

[seahorse5]

Re: Old 30 horse Johnson Update

According to an early Johnson service manual, the RD 18 - 30hp used bushings for the connecting rod to wrist pin. The next year, for the first 35hp - rd 19 - they used twin press-in needle bearings for the small end of the rod.<br /><br />Use 24:1 fuel oil mix on your 30hp.<br /><br />---------------------------------<br /><br />You can always tell an engineer, but you cannot tell him much.

 

[WillyBWright]

Re: Old 30 horse Johnson Update

I stand corrected.

 

[JasonJ]

Re: Old 30 horse Johnson Update

Thanx guys, when its a 50s motor I always assume 24:1 unless told otherwise, glad I stuck with that. Yeah, the pressure tank thing is a pain. I know there is a conversion to "normal", although I do not know what that entails. I see pressure tanks pop up on Ebay on occasion. I have also considered the difficulty of converting a regular plastic 6 gallon tank to pressure, it can't be that difficult. Just run the second hose to a sealed fitting installed on top of the tank. I'll toss that around unless someone has seen someone die because of it. Yeah, I remember the always entertaining thread on converting a regular 1 gallon gas can to a fuel tank, but this is different. We'll see. I have my pest sprayer for continued testing.

 

[oldboat1]

Re: Old 30 horse Johnson Update

sounds like you are in pretty good shape. If you are up and running, you can adjust the slow speed needle setting (in between squirts from your injector bottle, I guess). Stay with the 24:1 mix. It's also the correct mix for my '57 Big Twins, and they run fine on it. It's not difficult to pull the carb and clean it, although it sounds like that might not be necessary in your case -- might end up doing so if you can't get the motor to idle down smoothly, but you may not be able to do that anyway until you get a tank. The pressure tank system is really a good-working system, even if the upkeep required a little more -- would recommend picking up a tank rather than converting to a fuel pump.<br /><br />good luck.

 

[Chinewalker]

Re: Old 30 horse Johnson Update

I would not recommend trying to convert a plastic tank to a pressure tank. They're simply not made to be pressurized - they bloat up enough if you leave them in the sun as it is...<br />- Scott

 

[JasonJ]

Re: Old 30 horse Johnson Update

That is true. I think I'll explore the conversion concept instead. It'll make it easier to sell if a person knows they don't have to hunt up a pressure tank.

 

[Chinewalker]

Re: Old 30 horse Johnson Update

Hi Jason,<br /> The easy route is to find a 1960s Johnrude 28/33/40hp as they already have the fuel pump stuff you'd need to convert the ol' 30hp.<br /> I checked out your webpage - love the Red Band Merc! I've got several myself - 4hp in pieces, 9.8hp, 20hp, 35hp, and a 50hp in pieces. Also liked the conversion you did - I've considered that very same type of project myself, as a frend of mine has a graveyard with several dozen old shells that would work perfectly with that sort of conversion. I re-did an old Starcraft a few years ago, adding new stringers, foaming, etc. Very gratifying work... Great job on your rig! <br />- Scott

 

[sbump26]

Re: Old 30 horse Johnson Update

JasonJ glad you got the motor running. I bought a 55 10hp (QD-16) with a tank for 45.00 at a garage sale. Have 40.00 in parts, impeller, shift connector, carb. bowl gasket, tank gasket, and a few other small items. Runs pretty good, starts on 1st pull after warmed up. Need to figure way to keep the carb. knobs from spinning. Vibration makes them move, causing it to kill itself. Will idle pretty good, but going WOT under load, cuts out a lot. I don't know compression yet, but wonder if carb. kit would fix that and would carb. kit include the needle valves and seats that might fix the knob loosening. I also wonder how much pressure the tank can take. After running about 10 minutes, removing the gas cap to release pressure and there is a lot on it! Does it vent sometime or continue to pressurize the tank as it runs? I have the same plugs in mine as were recommended for yours. Are they the correct ones for my 10hp also? I gotta tell all you guys here that before finding this site, I would not have known what to do to get it going. I would have never thought to check the water impeller and replaced it. Probably would have burned it up and not known why. This is by far the best web site for fixing outboard motors. Also great job on the Skanky Beast.

 

[alcan]

Re: Old 30 horse Johnson Update

Sbump, needle valves do not come with a carb kit. You will get a float valve which consists of a needle and seat (different). The problem you describe with vibration on your high and low speed needles is easily cured. There are packing nuts where the needles enter the carb. I believe they are 7/16" and made of brass. You may just need to snug these nuts up a bit. You may find it necessary to replace the packing. Packing washers use to come with a carb kit, I haven't noticed for a while. When go to tighten the nuts back out the needles first. This will prevent jambing the needle into it's seat and causing damage. As far as I know there is no way to over presure the original presure tanks. They do have a bleed valve if this were to occur. In nearly fourty years of running these tanks I have never heard of anyone have an over presure problem. The biggest problem lies in trying to keep enough presure in the tank so the motor will run. I am not trashing the system. If one understands and maintains the presure tank system, it will be safe and reliable.

 

[oldboat1]

Re: Old 30 horse Johnson Update

If you are still intent on selling, adding a pressure tank will give you a quicker sale and increase the value. I've done the conversion as well as refurbishing a couple of tanks -- working on the tanks isn't any more difficult. Whether one is more expensive than the other probably just depends on what parts you have available or easy access to. I don't have a stake in pressure tanks, but they seem to get a lot of bad press which might not be entirely accurate --and they are not that rare, particularly if you don't mind tinkering with them a little bit. I know the pretty ones sell for some bucks on Ebay, but I think there might be some buyer inexperience driving that (or some successful hype).<br /><br />(Whoa -- where did all that come from?)

 

[alcan]

Re: Old 30 horse Johnson Update

What Oldboat says is true about the depenabilty. And also that these tanks are not that rare, how ever they are getting harder to come by. It is how ever rare to find a presure tank any more that is in serviceable condition. after all these units are 40-50 yrs old now. You can still find them at garage sales etc for $10-$20. The trouble is that most of them are half full of the foulest smelling nucular waste, won't hold presure, need paint and need to be over hauled. Repairing all this is no really technical job. Anyone can do it. When I put my time in these tanks, I am going to get paid. A brand new tank and hose for a modern motor can well exeed $100. If you pay full retail for a conversion kit it can be more yet. I concider these tanks a credit card to inexpencive outboards. If you have a good tank you can get all the motors you want. The way it seems to work for me is, a fellow buy's a tank from me, and I throw in a 25-35 hp motor. When the motor quits he can send it to the bottom and come get another, or I will buy back the tank.

 

[oldboat1]

Re: Old 30 horse Johnson Update

Alcan makes an interesting point about a working tank providing access to a bunch of inexpensive outboards. I'm just a hobbyist, but I have three working tanks and really used only one all last summer for five or six motors I was either running or tinkering with. If you have a tank, you have access to all those motors out there that invariably don't come with tanks (pretty rare that they do, and usually more expensive if the tank is included). Heck, JasonJ -- Pick up a couple of tanks. Get them both working. Sell one with the Johnson, and keep one for the next '56 you pick up and want to play with.

 

[Chinewalker]

Re: Old 30 horse Johnson Update

OldBoat and Alcan make good points. I haver several of these tanks and they are not that hard to find. If you go to an AOMCI meet or two you can generally pick up all you want. I saw about twenty of them at a meet last summer, none more expensive than about $60.00. Make sure the connector comes with it.<br />There are rebuild kits out there that include hose, diaphrams, gaskets, etc. Saw some on eBay last week for less than $25.00. <br />I have one that's my "shop tank" that has 16:1 fuel mixed for fresh motors, one that's my boat tank that keeps 24:1 in it, and another that's my show tank - fresh paint, new decal, etc. If you poke around enough, you'll likely have some given to you. Had a neighbor who was cleaning out an old shed that was falling down. Gave me three tanks for motors he no longer owned... Talk it up enough and the stuff will come to you...<br />- Scott

 

[rickdb1boat]

Re: Old 30 horse Johnson Update

fuel tank<br /><br /> Fuel Tank 2 <br /><br /> laingsoutboards.com fuel tank

 

[JasonJ]

Re: Old 30 horse Johnson Update

Did a compression check on this old thing today. Both cylinders are about 90 psi cold, not too bad. I was bored. I'll keep my eye out for a pressure tank, but I'll also see if I can get the pulse pump cheap, and go that route. If I do decide to sell it, it would sell easier if it can be used in a normal setup, and if I decide to keep it, it would be nice for it to have the normal setup.